Basic Hotel Information
Definition: a commercial establishment offering lodging to travelers and sometimes to permanent residents, and often having restaurants, meeting rooms, stores, etc., that are available to the general public.

There are a ton of subjects related to the Keyword “Hotel”, below are a few Popular well paying Niches…

Specific Hotel Niches
Cheap Hotels
Hotel Rooms 
Beach Hotels 

Ideas
There are many Options for creating Hotel based Web Site, here are a few Example:
Hotel Review Web Site 
Hotel Deal Web Site 

However, the Hotel, as a Keyword, is a very broad topic, so there are many possibilities available. 

Tips
Even the Specified Keywords above are Heavy in Competition, choose an even more specific Niche. You can be creative and mix Keywords to come up with a more specific Niche. Example: Cheap Beach Hotels in Panama Florida Reviews.

Also, take advantage of sites that may help. Looking around I found Hotel Internet Marketting which provides many good tips.